1. Field of the Invention
This invention generally relates to methods and systems for determining composition and completion of an experiment. Certain embodiments relate to methods and systems for determining composition and completion of an experiment based on one or more characteristics of data acquired during the experiment.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.
Generally, flow cytometers are used to perform measurements of fluorescence intensity of laser excited polystyrene beads or cells as they pass linearly through a flow chamber. However, flow cytometers can also be used to perform measurements of one or more properties of other particles. Some systems are configured to perform measurements of the level of light scattered by particles at 90° or 180° to the excitation source, two or more measurements of fluorescence used to determine classification, which is the particle “identity,” and additional fluorescence measurements known as “reporters,” typically used to quantify chemical reactions of interest. Each of the fluorescent measurements is made at a different wavelength or waveband of emission.
As the measurement capability of flow cytometer type measurement instruments has improved, the applications in which flow cytometers can be used to perform measurements has increased drastically. For example, flow cytometers have become increasingly useful in providing data for applications such as biological assays (e.g., displacement or competitive assays, non-competitive assays, enzyme assays), nucleic acid analysis, and combinatorial chemistry. In particular, the popularity of flow cytometer measurements has dramatically increased due to the speed with which assays can be performed by flow cytometers particularly in comparison to other assay methods (e.g., conventional enzyme linked immunosorbent assay “ELISA” format).
Imaging using detectors such as charged coupled device (CCD) detectors is also employed in several currently available instruments for biotechnology applications. Many of the commercially available systems are configured to image human (or other animal) cells. Such systems are not configured to generate images at different wavelengths or wavebands of fluorescence emission such that the images could be used to determine the identity of the cells or subset to which the cells belong. Instead, for multiplexed applications in which CCD detectors are used to measure fluorescent emission of cells, the subset or class of cells or other particles is determined based on the absolute position of the fluorescence emission within the image rather than the characteristics of the fluorescence emission such as wavelength composition.
When performing multiple assay tests simultaneously (i.e., in a single experiment), it is often necessary to indicate the tests (e.g., particle “identities,” fluorescence spectral addresses, position of fluorescence emissions, etc.) included in the experiment before the experiment begins and to define experiment parameters that can be used to determine when the experiment is complete. Selecting the various tests that are included in a particular experiment, from all of the possible tests that could be included in a multiplex test experiment, is time consuming, can lead to errors, and obligates the user to know ahead of time which tests are included. In addition, users of multiplex systems sometimes use different tests for different samples within a single experiment. In this manner, users are required to: 1) identify all of the tests included in the entire experiment for all of the samples regardless of which subsets of tests are used for particular samples; and 2) designate a “total count” threshold so that data acquired for each test is permitted to be recorded regardless of whether the tests are used for each sample. These requirements for the user are disadvantageous for at least the reasons set forth above.
Accordingly, it would be desirable to develop methods and systems for determining composition and completion of an experiment such that the need to indicate the individual tests included in the experiment before the experiment and to supply parameters that indicate when the experiment is completed are eliminated.